The overall goal of this three-year cooperative agreement application for a demonstration project is to compare the effects of two interventions, a usual care intervention and an intensive outpatient intervention consisting of both initial and extended intervention components, for homeless individuals with alcohol and/or substance abuse problems in the greater Birmingham area. This application arises from a collaborative effort between the University of Alabama at Birmingham (UAB) and the sub-contractor for the application, the Birmingham Health Care for the Homeless Coalition (BHCHC). Investigative team members at UAB have extensive experience in scientific, evaluation, administrative, and substance abuse aspects relevant. to the proposed project. investigative team members from the BHCHC have extensive experience in providing medical, substance abuse, mental health, and supportive services for homeless persons in the greater Birmingham area. Collectively, the investigative team represents an extremely strong group to participate collaboratively with representatives of NIAAA and NIDA to conduct the proposed cooperative demonstration project. A randomized, controlled design is proposed with a total of 150 homeless participants to be recruited and randomized to one of the two interventions, usual care or intensive outpatient intervention. Both process and outcome measures will be used throughout the intervention period and six months after discharge to compare the groups. Our major hypotheses include: 1) the intensive outpatient intervention will result in greater reduction in consumption of alcohol and/or other drugs than usual care; 2) the intensive outpatient intervention will increase levels of shelter and residential stability more than usual care; and 3) the intensive outpatient intervention will enhance the economic and employment status of homeless persons more than usual care.